Recently, biotechnology has proposed the possibility of new solutions to the food, environmental, and health problems as a final goal of human welfare, and among them, a technique using stem cells is emerging as a new technique of incurable disease treatment. For this disease treatment of the human, organ transplantation, gene therapy, and the like have been proposed before, but efficient commercialization is not sufficient due to immune rejection, supplied organs shortage, and lack of knowledge about vector development or disease genes. As a result, an interest in the stem cells is increased, and totipotent stem cells having ability to generate all organs through proliferation and differentiation are recognized to treat most of diseases and essentially solve organ damage. Further, many scientists have variously proposed potential to the stem cells up to treatments of Parkinson's disease which has been incurable, various cancers, diabetes and spinal cord injuries, and the like, as well as regeneration of almost all organs of the human body.
The “stem cells” refer to cells having self-replication capacity as non-differentiated cells and a differentiation capacity into two or more different kinds of cells. The stem cells classified into totipotent stem cells, pluripotent stem cells, and multipotent stem cells according to differentiation capacity, and also may be classified into embryonic stem cells and adult stem cells according to a cytological origin. The embryonic stem cells are derived from an embryo before implantation or a fetus genital tissue during generation; while the adult stem cells are derived from all organs present in the adult, for example, bone marrow, brain, liver, pancreas, and the like.
Since the embryonic stem cells have ethical issue, there is a limitation to be used as a cellular therapeutic agent. On the other hand, the adult stem cells can be mainly extracted from fat, umbilical cord blood, bone marrow, placenta, and the like and have no ethical problem. Particularly, fat stem cell in a fat tissue and placenta stem cells in the placenta during parturition are stable and have excellent differentiation to be used for improving symptoms of various cell damage diseases such as diabetes, dementia, arthritis, myocardial infarction, cerebral infarction, and renal failure which are incurable diseases which are not treated with modern medicine.
Among them, in the case of the stem cells derived from the placenta, by using the placenta discarded after childbirth, it is advantageous that extraction is easy and a large amount of stem cells can be easily ensured. The stem cells derived from the fat or the bone marrow are influenced by ages or health states of donors to be isolated and extracted to have a limitation in proliferation or differentiation capacity and have large variability. However, the ability of the stem cells derived from the placenta are not almost influenced according parameters such as ages of donors as stem cells which may be obtained in the earliest stage among the adult stem cells, and also, such stem cells have excellent proliferation and differentiation abilities. Further, from the stem cells derived from the placenta, a stem cell group which can be used for various diseases such as nervous system disorders, liver diseases, and musculoskeletal diseases may be isolated.
Due to the aforementioned advantages, researches on the stem cells derived from the placenta have been actively conducted. For example, in Korea Patent Registration No. 818214, a method of isolating stem cells from an amniotic membrane or a decidua by using a medium including N-acetyl-L-cysteine (NAC) is proposed, and Korea Patent Registration No. 871984, a method of culturing stem cells derived from an amniotic membrane, a serous membrane, a basal decidua, and a placenta tissue by using a medium including a basic fibroblast growth factor (bFGF) is proposed, and in Korea Patent Publication No. 10-2007-0052204, a method of isolating stem cells from a chorionic villi of a chorionic trophoblast layer of the placenta is proposed. However, until now, researches on stem cells derived from a pure chorionic trophoblast layer which is a part of the tissues of the placenta are not yet conducted.